Plasticator and molding system and method

ABSTRACT

A system and method are disclosed for molding a part, such as a point-of-purchase display, is shown. The system comprises a plasticator and press. The molded part comprises an in-molded graphics sheet which becomes molded integral with the part.

RELATED APPLICATION

[0001] This application is a continuation-in-part of application Ser.No. 08/220,906 filed Mar. 31, 1994.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to a system and method for molding parts,and more particularly, a system and method for molding parts fromcontaminated molding materials using a single thermal heat rise.

[0004] 2. Description of Related Art

[0005] In the field of thermoplastic molding, it is common to mold partsusing either an injection or compression molding process. Due to thesize of the orifices used in the injection molding equipment, it isoften difficult to injection mold with reinforcing fibers, such as glassfibers, having a length over one-eighth inch because such fibers are noteasily injected into or conveyed through the injection mold equipment.In addition, it is difficult to use contaminated molding materials suchas those collected in plastics recycling programs unless they have beensubstantially cleaned, processed and put into a usable form and sizeprior to being used in the injection molding equipment. Such cleaningand processing are expensive and can substantially increase the cost ofusing the contaminated materials, thereby making them economicallyimpractical.

[0006] Another problem with the thermoplastic processes of the past isthat the thermoplastics become degraded and lose, for example, theirstrength when exposed to multiple heat rises.

[0007] In general, there are two basic types of compression moldingprocesses which may be used for molding thermoplastics. First, a sheetmolding process involves placing a reinforcement, such as a glass mat,between sandwiching layers of a thermoplastic and heating the materialsto produce a single sheet of material. The single sheet of material isthen cut to the desired size and then reheated to molding temperaturebefore being placed in a compression molding press. This process has thedisadvantage of higher cost because of the apparatus required, thematerial handling costs incurred in making the sheet, handling andcutting the sheet, and the like. The material used to make the sheet isalso subject to three thermodynamic cycles, a first cycle when thethermoplastic sheet is formed, a second cycle when the thermoplasticsheets and glass mat are molded together, and a third cycle when theresulting sheet is heated to molten temperature prior to molding thepart.

[0008] The second form of thermoplastic compression is bulk moldingcompounds by producing a billet of molten material that is placed into acompression molding press which molds the molten material into a part.Effectively placing and distributing long reinforcing fibers in thebillet has heretofore required complex machinery. For example, U.S. Pat.No. 5,165,941 issued to Ronald C. Hawley on Nov. 24, 1992, discloses anextruder apparatus and process for compounding thermoplastic resin andfibers. The Hawley extruder includes an apparatus for compoundingthermoplastic resin and reinforcing fibers incorporating a resinextruder in which thermoplastic resin pellets are melted in a second,compounding, extruder in which the molten thermoplastic resin is mixedin intimate contact with long reinforcing fibers. The meltedthermoplastic resin is not fed into the device with the fibers, butrather is introduced into the compounding extruder at a point downstreamof the inlet point for reinforcing fibers, so that the fibers aremechanically worked and heated before coming into contact with heated,molten thermoplastic resins.

[0009] The Hawley device generally suffers from complexity that raisesthe investment and maintenance costs.

[0010] The compression molding of products using polymeric material andglass fibers has traditionally produced a material referred to as fiberglass reinforced plastic. This material exhibits characteristics betterthan the reinforced plastics, but does not exhibit strength, elasticityor impact resistance comparable to thermoplastic materials which arespecifically designed to exhibit these characteristics. Most fiberglassreinforced plastic currently in the market is thermoset and isessentially a solidified mixture of fiber glass and plastic withoutbenefit of chemical bonding or specific methods of enhancing polymerentrapment of the glass fibers because the glass fibers are merelyimmobilized in the resin in which it is embodied.

[0011] In addition, thermoset materials are generally not recyclableother than as filler materials, while thermoplastic materials can beremelted and remolded.

[0012] In the field of molded parts, many products are currently madefrom a variety of materials using moldable plastic. In the sportinggoods field for example, example, bicycles, basketball backboards, toyvehicles and the like are commonly produced using multiple plasticmaterials. Compression molding has been a common method for producingbasketball backboards and related parts of basketball goal assemblies,such as the support pull for the basketball backboard for many years.Heretofore, compression molding of basketball backboards and relatedparts has typically been limited to thermoset materials, which ischaracterized by placement of a cold charge in a compression mold.Thermoset process materials have certain drawbacks, including the factthat these material are generally not recyclable other than as fillermaterials. In general, there are two basic types of compression moldingprocesses which may be used for molding thermoplastics. The followingdescription of these two processes outline some of the difficulties thathave prevented use of compression molding thermoplastics in thebasketball goal assembly field.

[0013] The first type is a sheet molding process that involves areinforcement, such as a glass mat, between sandwiching layers of athermoplastic and heating the materials to produce a single sheet ofmaterial. The single sheet of material is then cut to the desired sizeand then reheated to molding temperature before being placed in acompression molding press. This process has the disadvantage of highercost because of the apparatus required, the material handling costincurred in making the sheet, handling and cutting the sheet, and thelike. The material used to make the sheet is also subject to threethermodynamic cycles, a first cycle when the thermoplastic sheet isformed, a second cycle when the thermoplastic sheets and glass mat aremolded together, and a third cycle when the resulting sheet is heated tomolted temperature before molding the part.

[0014] A second form of thermoplastic compression is bulk moldingcompounds by producing a billet of molten material that is placed into acompression molding press which molds the molten material into a part.Effectively, placing and distributing long reinforcing fibers in thebillet has heretofore required complex machinery as discussed in detailin parent application Ser. No. 08/220,906.

[0015] In addition, in recent years it has been increasingly common toprovide graphics on the front face of molded parts, including thebackboard, for a variety of reasons, such as aesthetic appeal to theconsumer, product and source identification, and the like. However, theonly commercially acceptable method of applying graphics have beensilk-screened with inks or by applying decals.

[0016] Silk-screening is time consuming and tends to fade afterprolonged exposure to sunlight and the elements. Decals are alsoexpensive and can peel off after time.

[0017] An example of a prior art basketball backboard with silk-screengraphics is a backboard sold as “ShurShot”. The silk-screen ShurShotbackboard is believed to be about 48 inches across and mates astructurally foam polystyrene molded in a multiple-port injectionprocess. The backboard is molded in the natural color of polystyrene,which is milky white. The entire ShurShot backboard is subsequentlyspray painted both to seal the polystyrene and to protect the backboardfrom ultraviolet radiation. Finally, graphics are silk-screened on thefront face of the backboard.

[0018] In some prior art applications, a graphics display was printed ona styrene sheet and laid by hand into a mold for forming the backboard.Alignment of the sheet was accomplished by aligning holes in the sheeton pins in the mold provided for producing the mounting holes in thebackboard. Upon injecting styrene into the mold, the back portion of thegraphics sheet melted to cause it to be joined to the face of thebackboard. As styrene is relatively easy to print on, its use in thisprior art process was conducive to the production of backboards providedwith sheets having graphics printed thereon.

[0019] One of the problems encountered with printing on parts orbackboards molded using the system of the parent application Ser. No.08/220,906 was that printing on polyolefin materials was difficultbecause the polyolefin-based materials were relatively non-porous and,therefore, not receptive to printing inks.

[0020] What is needed, therefore, is an apparatus and method for moldingthermoplastic parts which is simple and economical and which preservesthe length of the reinforcing fibers, evenly distributes the reinforcingfibers or any other filler materials while maintaining flexibility ofthe material type in products fabricated, is capable of capitalizing onuse of various contaminated thermoplastics to allow use of post consumerrecycled material, and which provides a compounding and fabricationenvironment which promotes chemical bonding and molecular orientation toenhance the characteristics of the molded part.

[0021] The foregoing also demonstrates the need for a compressionmolding apparatus and method for making parts, such as sporting goodsequipment including basketball backboards from recycled thermoplasticmaterials without requiring the extensive cleaning and processing thatheretofore has made use of thermoplastics for these products inpractical. There is also a need to improve the in-mold graphics processto permit the basketball backboard and other plastic molded parts ofbasketball goal assemblies to be compression molded with thermoplasticresin materials having improved in-molded graphics.

SUMMARY OF THE INVENTION

[0022] It is therefore a primary object of this invention to provide amethod and apparatus which facilitates overcoming one or more of theaforementioned problems.

[0023] In one aspect of the invention, this invention comprises aplasticator for creating a billet of moldable material including afeeder for receiving a plurality of molding materials comprising apredetermined amount of a polyester, other carbocyclic and reinforcingfibers and a suspender coupled to said feeder for receiving the moldingmaterials, for creating a molten suspension of the molding materialswithout damaging a substantial number of the reinforcing fibers, andalso for creating the billet.

[0024] In one aspect of the invention, this invention comprises aplasticator for creating a billet of moldable material including afeeder for receiving a plurality of molding materials comprising apredetermined amount of a polyester, other carbocylics and reinforcingfibers, and a suspender coupled to the feeder for receiving the moldingmaterials, for creating a molten suspension of the molding materialswithout damaging a substantial number of the reinforcing fibers, andalso for creating the billet.

[0025] In another aspect of the invention, this invention comprises amethod for creating a billet for molding a part comprising the steps of(a) loading a plasticator with molding materials, the molding materialscomprising a polyester, other carbocylics and reinforcing fibers, (b)heating the molding materials to a predetermined temperature, (c)blending the molding materials in order to create a molten suspensionwherein a majority of the reinforcing fibers remain generally undamaged,and (d) extruding the molten suspension in order to form a billet havingpreselected billet characteristics.

[0026] In yet another aspect, this invention comprises a plasticator forcreating a billet from a plurality of molding materials, the plasticatorcomprising plasticating means for receiving the molding materials andfor creating a molten suspension of the molding materials, and controlmeans associated with the plasticating means for controlling thesuspension characteristics applied to the molding materials in order toplasticity the plurality of molding materials into a billet havingpredetermined billet characteristics.

[0027] In still another aspect, this invention comprises a system formolding a part comprising a plasticator for creating a billet from aplurality of molding materials, the plasticator comprising plasticatingmeans for receiving the molding materials and for creating a moltensuspension of the molding materials, control means associated with theplasticating means for controlling the suspension characteristicsapplied to the molding materials in order to plasticity the plurality ofmolding materials into a billet having predetermined billetcharacteristics, and a press having a mold for receiving the billet andfor molding the billet into the part.

[0028] In yet another aspect, this invention comprises a plasticatingprocess comprising the steps of loading a plasticator with a pluralityof molding materials, creating a mixture with the plurality of moldingmaterials in the plasticator, and plasticating the mixture of theplurality of molding materials at a controlled temperature and pressurein order to create a billet having predetermined billet characteristics.

[0029] In a still further aspect, the invention comprises a screw foruse in a plasticator having a barrel, the screw comprising a root and aplurality of threads configured to permit a polyester, other carbocylicsand a plurality of reinforcing fibers to be mixed to provide a billethaving predetermined billet characteristics without damaging asubstantial number of the reinforcing fibers.

[0030] It is an object of this invention to provide a system and methodfor using long reinforcing fibers that can be loaded simultaneouslyalong with the thermoplastics being used.

[0031] Another object is to facilitate providing a system and methodwhich is simple and economical and which provides a process thatgenerally preserves the length of the reinforcing fibers through theplasticating and molding process.

[0032] Another object of this invention is to provide a method andapparatus which evenly distributes any filler materials, such asreinforcing fibers, which are used in the apparatus and method.

[0033] Still another object of the invention is to provide a method andapparatus which facilitates using contaminated molding materials whichhave heretofore been undesirable for use because of their contaminationor because they are expensive to clean sufficiently for use.

[0034] Still another object of this invention is to provide a method andapparatus which facilitates or enhances chemical bonding and molecularorientation of the polymer molding materials being used.

[0035] Yet another object is to provide a system and method forefficiently and effectively in-molding graphics into a part such as abasketball backboard or other sporting equipment.

[0036] In a still further aspect of the invention this inventioncomprises a plasticating process comprising the steps of loading aplasticator with a plurality of molding materials, creating a mixturewith the plurality of molding materials in the plasticator, andplasticating the mixture of said plurality of molding materials at acontrolled temperature and pressure in order to create a billet havingpredetermined billet characteristics.

[0037] In another aspect of the invention a process for molding a partcomprises the steps of placing a sheet into a mold prior to molding,placing a billet onto the sheet, compression molding the sheet and thebillet to produce a part such that the sheet becomes integrally moldedwith the part.

[0038] In another aspect of the invention a molded part comprising acompression molded part molded from a plurality of materials comprisinga predetermined amount of a reinforcing fiber and thermoplasticpolymers, a sheet integrally molded into said part, the sheet comprisinga graphics side facing away from the part.

[0039] In still another aspect of the invention a basketball backboardcomprising a backboard member molded from a plurality of materialscomprising a predetermined amount of a reinforcing fiber andthermoplastic polymers, and a sheet integrally molded into the backboardmember, the sheet comprising a graphics side facing away from the part.

[0040] These objects and others will be more apparent when the followingdescription is read in conjunction with the claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0041]FIG. 1 is a view of a system according to one embodiment of theinvention, comprising a plasticator and a press;

[0042]FIG. 2 is a fragmentary view of the plasticator shown in FIG. 1;

[0043]FIG. 3 is a fragmentary sectional view showing a screw positionedin a barrel which may be used in the plasticator shown in FIGS. 1 and 2;

[0044]FIG. 4 is a view similar to FIG. 3 showing a screw having aplurality of pitch diameters or distances;

[0045]FIG. 5 is a sectional view showing the beginning of theplasticating process;

[0046]FIG. 6 is a sectional view similar to FIG. 5 showing the screwwithdrawing from a passageway in the barrel;

[0047]FIG. 7 is another view showing the screw withdrawing further fromthe passageway in the barrel;

[0048]FIG. 8 is a view similar to FIG. 7 showing a knife blade in anopen position;

[0049]FIG. 9 is a view showing the screw acting as a plunger and forcingthe mixed suspension of molding materials out of an extrusion end of thebarrel;

[0050]FIG. 10 is a view similar to FIG. 9 showing the knife in theclosed position, thereby severing the mixed suspension of moldingmaterials to provide a billet;

[0051]FIG. 11 is a top view showing a screw drive system in a homeposition;

[0052]FIG. 12 is a view similar to FIG. 11 showing the screw drivesystem withdrawing the screw from the barrel;

[0053]FIG. 13 is another view showing the screw drive system after ithas withdrawn the screw further from the barrel;

[0054]FIG. 14 is an end view of the plasticator showing a knife assemblyused in the plasticator;

[0055]FIG. 15 is a view similar to FIG. 14 showing a knife activated toa fully open position; and

[0056]FIG. 16a and 16 b, taken together, are schematic diagrams showinga process according to an embodiment of the invention.

[0057]FIG. 17 is an exploded view illustrating a mold for manufacturinga basketball backboard;

[0058]FIG. 18 is a front view of the basketball backboard manufacturedin accordance with the mold shown in FIG. 17;

[0059]FIG. 19 is a fragmentary side view of the basketball backboardshown in FIG. 18;

[0060]FIG. 20 is a rear view of the basketball backboard shown in FIG.18 illustrating various ribs which facilitates strengthening thebackboard; and

[0061]FIG. 21 is a view of a point-of-purchase display manufactured inaccordance with an aspect of this invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0062] Referring now to FIG. 1, a system 10 for molding a part is shown.The system 10 comprises a plasticator 12 for receiving a plurality ofmolding materials 14 and also for plasticating the molding materials 14into a billet 16. The system 10 also comprises a press 18 associatedwith the plasticator 12 for receiving the billet 16 and for molding thebillet 16 into the part (not shown) defined by a mold 20.

[0063] The plasticator 12 comprises a base 22 which supports the variouscomponents of the plasticator 12. The base 22 has a support column 24which supports a stationery block 26. The plasticator 12 comprises asuspender or barrel 28 having a feeding end 28 a mounted to thestationery block 26. The plasticator 12 also comprises a screw 30 (FIG.3) which is rotatable and axially mounted in barrel 28 as describedbelow.

[0064] The system 10 comprises a controller/microprocessor 32 forcontrolling the operation of the plasticator 12 and press 18. Thecontroller 32 includes an operator control box 34 for interfacing withcontroller 32. A suitable controller is the Model Slick 150 manufacturedby Allen Bradley of Fairfield, N.J., but it should be understood thatany suitable controller which is capable of controlling the operation ofthe system may be used.

[0065] As best illustrated in FIG. 1, the plasticator 12 furthercomprises feeding means or a feed hopper 36 having an opening 38 forreceiving the molding materials 14. The feed hopper opening 38 may bedirectly connected to a supply system (not shown) for moving materialsfrom a storage or drying area (not shown) to the system 10.

[0066] The feed hopper 36 may include an agitator 40 (FIG. 2) forfacilitating agitating and mixing the molding materials 14. The agitator40 is coupled to a drive motor 42 which in turn is coupled to a controlbox 44 which controls the speed and operation of the drive motor 42. Inone embodiment, the control box 44 is coupled to controller 32, therebypermitting the controller 32 to control the operation of the drive motor42. The drive motor is an electric drive motor, but it could be anysuitable type of motor for driving the agitator, such as a hydraulic orpneumatic motor.

[0067] The feed hopper 36 has an end 36 a coupled to stationery block 26so that the molding materials 14 may be fed into a feeding opening 46(FIG. 3) in the feeding end 28 a of barrel 28.

[0068] The feeding means or feed hopper 36 may comprise a preheater 48(FIG. 1) which is coupled to controller 32 for preheating the moldingmaterials 14 to a preheated temperature before the molding materials 14are introduced into the feeding opening 46 in barrel 28. In theembodiment being described, the preheater 48 may preheat the moldingmaterials 14 in feed hopper 36 to between 100 and 300 degreesFahrenheit, depending on the molding materials 14 selected and used.Although not shown, the feed hopper 36 may be insulated to facilitatemaintaining the temperature in the feed hopper at the preheatedtemperature.

[0069] The suspender or barrel 28 has a feeding end 28 a and also anextruding end 28 b from which billet 16 is extruded. In one embodiment,the barrel 28 is approximately four feet long and has an outsidediameter of approximately eight inches and an inside diameter ofapproximately four inches. The barrel 28 is manufactured from hardenedsteel and weighs approximately 300 pounds. The barrel may have a die 50located at the extruding end 28 b. The function of the die 50 is tocause the billet 16 to be extruded into a predetermined shape ordiameter. For example, the billet 16 may be extruded so that itscross-sectional diameter is approximately 2.0 inches.

[0070] As illustrated in FIGS. 3-10, the barrel 28 comprises a feedingportion 54, a blending portion 56 and an extruding portion 58. Theplasticator 12 also comprises the screw 30 which is rotatively andaxially mounted in a passageway 52 defined by barrel 28. Notice thatscrew 30 comprises a feeding end 30 a and an extruding end 30 b. Thescrew 30 further comprises a feeding section 60 associated with thefeeding end 30 a, a blending section 62, and an extruding section 64associated with extruding end 28 b. The feeding section 60, blendingsection 62 and extruding section 64 of screw 30 become generallyassociated with the feeding portion 54, blending portion 56 andextruding portion 58, respectively, of barrel 28 when the screw 30 islocated in a home position generally shown in FIGS. 3-5.

[0071] The feeding section 60 comprises a first plurality of threads 66.The blending section 62 comprises a second plurality of threads 68, andthe extruding section 64 comprises a third plurality of threads 70.

[0072] As illustrated in FIG. 3, the first plurality of threads 66 havea depth, identified by double arrow 72, which is generally greater thanthe depth, identified by double arrow 74, of the second plurality ofthreads 68 associated with the blending section 62 of screw 30. Thefirst and second plurality of threads 66 and 68 may have a depth whichis greater than the depth 76 of the third plurality of threads 70associated with extruding section 64. It is to be noted that screw 30comprises a shaft or a root or core 30 d about which the first, secondand third plurality of threads 66, 68 and 70 are located. As bestillustrated in FIGS. 2 and 3, the core 30 d may be generally tapered toprovide a screw depth that generally decreases from the feeding end 30 ato the extruding end 30 b. This facilitates ensuring that the depth 72of the first plurality of threads 66 is generally greater than the depth74 of the third plurality of threads 70.

[0073] Another embodiment of the screw 30 is shown in FIG. 4. In thisembodiment, the second plurality of threads 68 are provided with agreater number of threads (i.e., a smaller pitch or distance betweenthreads) than the first plurality of threads 66. The embodiments shownin FIGS. 3 and 4 facilitate controlling the mixture and suspension timeof the molding materials 14 and, further, mixing the molding materials14 with a predetermined pressure and shear, without significantlydamaging the molding materials 14 as the screw 30 rotates.

[0074] In one embodiment the screw 30 is approximately 100 inches longand has a core 30 d diameter of approximately 3.7 inches. The screw 30is a left-hand screw, and the depths 72,74 and 76 are 0.8 inch, 0.6inch, and 0.75 inch, respectively. The blending section 62 of screw 30has about 30% more turns in FIG. 4 when compared to the feeding section60.

[0075] The plasticator 12 also comprises means for driving screw 30 or ascrew drive system 75 for rotatably and axially driving the screw 30 ina passageway 52 (FIG. 3) of barrel 28. The screw drive system 75 iscapable of controlling the rotational and axial movement of screw 30 inthe barrel 28 in order to facilitate mixing the molding materials 14into a molten suspension and ultimately, into billet 16 having certainpredetermined characteristics. When the mixed molten suspension achievesthe predetermined characteristics, such as a predetermined volume,density, viscosity, or size as indicated by predetermined temperatureand pressure, then screw 30 is allowed to withdraw in the direction ofarrow 77 in FIG. 3 to permit the suspension to be formed into the billet16 at a storage or extruding area 124 of barrel 28. As described below,the screw drive system 75 is also capable of controlling the rotationalspeed of screw 30 and the axial movement of screw 30 until the desiredpredetermined characteristics are achieved.

[0076] The screw drive system 75 (FIG. 2) comprises means coupled toscrew 30 for rotatably driving screw 30 and also for axially drivingscrew 30 into and out of passageway 52 (FIG. 2) in barrel 28. The meanscomprises a slidable block 78 which is slidably mounted on a pair ofstationary column supports 80 and 82, each having an end (such as 92 a)secured to stationary block 26. The means also comprises suitablebearings (not shown) located in slidable block 78 for facilitating theaxial movement of slidable block 78 in the direction of double arrow 84in FIG. 2.

[0077] The screw drive system 75 also comprises a block driver 86 forslidably driving the slidable block 78 in the direction of double arrow84. In the embodiment being described, the block driver 86 comprises apair of push/pull hydraulic cylinders 88 and 90 (FIGS. 11-13). The screwdrive system 75 also comprises a drive motor 92 which is coupled toscrew 30 and which rotatably drives screw 30 in either a clockwise orcounterclockwise direction as desired. In the embodiment beingdescribed, the drive motor 92 is a hydraulic motor which is capable ofrotating screw 30 at approximately 0 to 100 rpms.

[0078] The screw drive system 75 may comprise first sensing means orsensor 94 for sensing the rpms of drive motor 92. First sensing means 94may also include a torque sensor (not shown) which is coupled tocontroller 32 and which monitors or senses the torque of screw 30 as itproduces the billet 16.

[0079] The plasticator 12 comprises power means or a power system 96 forenergizing drive motor 92 and block driver 86. In the embodiment beingdescribed, the power system 96 comprises an electric motor 98 whichdrives a hydraulic pump 100. The hydraulic pump 100 pumps oil from areservoir 102 through filter 104 into control means or control block106. The control block 106 comprises pressure valves 108, 110, 112, 114and 116 which control the delivery of fluid to cylinders 88, 90, drivemotor 92 and to a knife driver 118 as described below. The pressurevalves 108, 110, 112,114 and 116 are coupled to controller 32 which iscapable of controlling their operation as described below.

[0080] The power system 96 may comprise a plurality of variable pressureregulators, such as regulator 117, which may be positioned between thedrive motor 92, cylinders 88 and 90 and their respective pressure valvesin order to facilitate controlling the hydraulic pressure deliveredthereto. For example, the pressure regulator associated with thecylinders 88 and 90 can be adjusted so that the pressure delivered tocylinders 88 and 90 can be varied. One suitable pressure regulator isthe Vickers regulator, manufactured by Vickers of Troy, Michigan. Thispermits an operator to vary the amount of pressure at which the slidableblock 78 is biased towards the stationary block 26.

[0081] As the screw drive system 75 drives and forces molding materials14 into a storage area 124 (FIG. 3) associated with the extrudingportion 58 of barrel 28, the pressure in the barrel 28 begins to build.Such pressure increases as more of the molten suspension of moldingmaterials 14 are forced and driven into the storage area 124. When suchpressure reaches or exceeds the predetermined pressure being deliveredto cylinders 88 and 90, the pressure causes screw 30 to withdraw frompassageway 52 as shown in FIGS. 3-5. Consequently, by controlling thepressure delivered to cylinders 88 and 90, the density, volume andviscosity of the molten suspension and the billet 16 can be accuratelycontrolled. By adjusting the pressure delivered to cylinders 88 and 90,the viscosity, volume and density of the molten suspension and billet 16can be made to conform to the desired material characteristics andcontrolled. Although not shown, other types of regulators may be used.For example, electronic or pneumatic regulators may be provided which iscoupled to controller 32 for automatically adjusting the pressuredelivered to cylinders 88 and 90 and drive motor 92.

[0082] As best illustrated in FIG. 2, the system 10 also comprisessensing means or a second sensor for sensing the pressure in the powersystem 96. In the embodiment being described, the sensing meanscomprises a pressure gauge 126 for measuring the pressure beingdelivered by the hydraulic pump 100. In addition, sensing means alsocomprise pressure gauge 128 for sensing the pressure being delivered tocylinders 88 and 90. Although not shown, it should be appreciated thatsensing means could comprise any suitable hydraulic, electronic or othersuitable means which are capable of sensing the pressure being deliveredby control block 106 to drive motor 92, knife driver 118, and cylinders88 and 90.

[0083] The plasticator 10 also comprises an adjustable distance sensor130 which senses the travel distance of screw 30 as it withdraws fromthe passageway 52 of barrel 28. When the actual travel distance reachesa preset distance, the distance sensor 130 generates a distance signalwhich is received by controller 32. Upon receipt of the distance signal,controller 32 energizes pressure valves 108, 110, 114 and 116 to shutthe fluid pressure being delivered to cylinders 88, 90 and drive motor92. As described later herein, controller 32 may then energize pressurevalve 112 to deliver fluid to knife driver 118 in order to drive knifeblade 120 into the open position shown in FIGS. 9 and 15. Controller 32may then energize control block 106 and pressure value 108 to actuatehydraulic cylinders to pull or slidably drive slidable block 78 towardsstationary block 26 which causes the molten suspension to be extrudedout of extruding opening 132 (FIG. 9) associated with the extruding end28 b of barrel 28. Controller 32 may then energize knife driver 118 toforce knife blade back into the closed position shown in FIGS. 10 and 14thereby severing the molten suspension to provide billet 16.

[0084] It should be noted that the distance sensor 134 comprises abracket 136 which has an end 136 a secured to slidable block 78. Thedistance sensor 134 also has a switch 138 secured to the bracket 136. Aplurality of contact switches are slidably mounted on a panel 148(FIG. 1) which is secured to stationary block 26. The panel 148 hasdistance indicia thereon, and the contact switches 140 can be slidablyadjusted on the panel 148 to generally correspond to the volume of thebillet 16 to be extruded from barrel 28. Thus, as slidable block 78moves in the direction of arrow 122 and thereby causes screw 30 towithdraw from passageway 52, contact switch 140, for example, contactsswitch 138, thereby generating the distance signal which is received bycontroller 32. Although not shown, it should be appreciated that thedistance sensor could be any suitable means for measuring the size,including volume, of the billet 16 which is being created. For example,other suitable electrical, optical, hydraulic, pneumatic, or other typesof sensors may be employed for measuring the distance the screw 30 andblock 78 travels.

[0085] The system 10 comprises heating means or a heater forplasticating the molding material 14 using a single thermal cycle fromintroduction of materials 14 to molding a part or product from billet16. As illustrated in FIGS. 1 and 2, the plasticator 10 comprisesheating means or a heater system, 150, in the embodiment beingdescribed, which comprises three sets of resistance or heating bands152,154 and 156. The heating bands 152,154 and 156 on the barrel 28 areassociated with the feeding portion 54, blending portion 56 andextruding portion 58, respectively, as illustrated in FIGS. 3-5.

[0086] The heating bands 152 heat the feeding portion 54 to a firstpredetermined temperature. Likewise, the heating bands 154 heat theblending portion 56 to a second predetermined temperature, and theheating bands 156 heat the extruding portion 58 to a third predeterminedtemperature. The heating bands 152, 154 and 156 are coupled to heatercontroller 158 which is capable of energizing the heating bands 152,154and 156 to heat barrel 28 the first, second and third predeterminedtemperatures, respectively. The heater controller 158 comprises a thirdsensing means or a third sensor for sensing the actual temperature ofthe feeding portion 54, blending portion 56 and extruding portion 58,respectively, of barrel 28. The heater controller 158 also comprisesdisplay means or a display consisting of displays 160 (FIG. 2) fordisplaying the actual temperature sensed by heater controller 158. Theheater controller 158 is coupled to controller 32 which may also controlthe operation of heater 150 in heating bands 152, 154 and 156. In theembodiment being described, the first predetermined temperatureassociated with the feeding portion 54 ranges from 300 to 500 degreesFahrenheit, depending on the molding materials 14 being used. Likewise,the second and third predetermined temperatures may also range from 300to 500 degrees Fahrenheit. Although these ranges are shown, they are notmeant to be limiting and other ranges may be appropriate, depending uponthe molding materials 14 and desired or predetermined billetcharacteristics being used.

[0087] Although not shown, the barrel 28 and heating bands 152,154 and156 may be insulated to facilitate minimizing heat loss in barrel 28.

[0088] The heating means may also include the preheater 48, a knifeblade heater, and a mold heater 182, to facilitate providing one thermalrise. In the embodiment being described, the mold heater 182 maycomprise Model Nos. S-8412 or 3412 Sterl-Tronic Temperature Controlmanufactured by Sterl Co. of Milwaukee, Wis. Furthermore, a screw heater(not shown) may also be provided to heat screw 30 to further facilitateheating the molding materials 14 in barrel 28.

[0089] The plasticator 12 also comprises a separator or knife assembly162 (FIGS. 14 and 15) for separating the molding materials 14 to providethe billet 16. The knife assembly 162 is associated with the extrudingends 28 b of barrel 28 and comprises a pair of L-shaped mountingbrackets 164 and 166 which define a channel 168. The knife assembly 162also comprises the knife blade or knife 120 which is slidable mounted inchannel 168. The knife blade 120 is coupled to knife driver 118 which iscapable of driving the knife from the closed position in FIG. 14 to theopen position in FIG. 15 and vice versa. The knife driver 118 comprisesa push/pull type cylinder in the embodiment being described which iscoupled to pressure valve 112 which in turn is coupled to controller 32as mentioned previously herein.

[0090] The knife assembly 162 comprises a pair of switches 170 and 172which cooperate with a trigger bar 174 located on knife blade 120. Thetrigger 174 triggers switch 170 to generate a closed signal when theknife 120 is in the closed position. Likewise, the trigger 174 causesswitch 172 to generate an open signal when the knife 120 is in the openposition. The switches 170 and 172 are coupled to controller 32 whichreceive the open and closed signals.

[0091] It should be appreciated that due to the proximal location of theknife 120 to the extruding end 28 b of barrel 28 and die 50, the knife120 becomes heated to approximately the same temperature as theextruding portion 58 of barrel 28. Note also that when the knife 120 isin the closed position, it seals the passageway 52 (FIGS. 3 and 4) ofbarrel 28 so that the molded suspension of molding materials 14 can beforced against the barrel side 120 a (FIG. 3) of knife 120. Although notshown, the knife 120 may also be provided with the knife heatermentioned above which would be coupled to controller 32 to facilitateheating the knife 120 to a predetermined knife blade temperature whichwould generally correspond to the third predetermined temperature.

[0092] The system 10 comprises press 18 (FIG. 1) which comprises a pressdriver 176 which is coupled to a press controller 178 which may also becoupled to controller 32. The press controller 178 may energize pressdriver 176 to drive platform 180 from an open or non-molding positionshown in FIG. 1 to a closed or molding position (not shown). Asillustrated in FIG. 1, platform 180 may have a mold member 20 a whichcooperates or mates with a complementary mold member 20 b to mold thepart. In the embodiment being described, the press 18 is a compressionpress like the 250 ton Bipel Press, manufactured by Bipel of England,and the press controller 178 may be a controller provided by AllenBradley which may be coupled to controller 32.

[0093] The press 18 also comprises the press heater 182 mentioned abovewhich is coupled to press controller 178 and which is capable ofcontrolling the temperature of the mold members 20 a and 20 b when theyare molding the part. In the embodiment being described, the mold heater182 can vary the temperature of the mold members 20 a and 20 b fromapproximately 30□ F to 350□ F depending on the molding materials 14being used. It is to be noted that the press 18 is a compression presswhich includes a pressure regulator 184 for regulating the pressuredelivered to the billet 16. In the embodiment being described, thepressure can vary from 0 psi to 4000 psi. The press 18 also comprises apressure gauge 186 and timer 188 for displaying the pressure and moldtime, respectively, during corresponding operation of the press 18.

[0094] The system 10 also comprises conveyance means or a conveyancesystem 190 (FIG. 1). The function of the conveyance system 190 is toposition billet 16 in mold member 20 b after billet 16 is extruded fromthe extruding end 28 b of barrel 28. In this regard, the conveyancesystem 190 may be any suitable means for conveying the billet 16directly into the press 18, such as robotic arm, a hydraulic cylinder, apneumatic cylinder, an electronic or mechanical conveyor or any othersuitable means for causing billet 16 to be positioned in press 18.Furthermore, the conveyance system 190 may also comprise means forconveying or positioning the plasticator 12 in operative relationshipwith the mold member 20 b such that when the billet 16 is extruded frombarrel 28, it drops directly onto mold member 20 b. In this regard, theconveyance system 190 may comprise a wheel, shuttle and trackarrangement (not shown) onto which the plasticator 12 may be positionedsuch that the plasticator 12 may be slidably moved towards and away frompress 18. For example, the shuttle and track system would be coupled tocontroller 32 so that when the press 18 moves to the open position shownin FIG. 1, the extruding end 28 b of barrel 28 is moved into operativerelationship underneath platform 180, such that when the billet 16 isextruded, it becomes positioned on mold member 20 b as shown in FIG. 1.The plasticator 12 may then be moved or shuttled away from press 18 andthe platform 180 driven downward (as viewed in FIG. 1) to mold the part.After the part is molded, it may be removed from the press 18 and,during such removal, the plasticator 12 may again be shuttled or movedto extrude the next billet 16 onto mold member 20 b. Other variations ofmoving the plasticator 12 may also be used. For example, the conveyancesystem 190 may cause the plasticator 12 to withdraw from press 18 slowlyso that the billet 16 is extruded substantially evenly over the lengthof the mold member 20 b when the billet 16 is placed in the mold.

[0095] The molding materials 14 are preferably comprised of a polyester192, a carbocyclic or other carbocylics 194 and a preselected filler 196(FIGS. 1, 16a and 16 b). In the embodiment being described, thepolyester 192 may include polyethylene terephthalate (PET), and thecarbocylics 194 may be an olefinic such as polycarbonate, polypropylene(PP), polyethylene (PE) or ethylene vinyl acetate (EVA).

[0096] The preselected reinforcement or filler 196 may comprise areinforcing fiber, glass fiber, fly ash, clay, carbon or graphite fiber,shredded reinforced fiber composite material, or like materials. It hasbeen found that this apparatus and method can use fibers introduced toplasticator 12 with the other molding materials 14, without the fibersincurring significant damage. It should be appreciated, however, thatthis apparatus and system could be used with reinforced fibers, such asglass fibers, which range from the smallest available to as long as 6inches.

[0097] A compatibility enhancing agent or agents 198 may also beincluded as one of the molding materials 14 which is added into feedhopper 36. It should be appreciated that the polyesters 192, carbocylics194, preselected fillers 196 and compatibility enhancing agents 198 maytake any suitable form which is capable of being received in the feedhopper 24, such as the form of chips, pellets, flakes and fibers. Inaddition, reinforcing fiber may take the form of single strands,shavings, mats, edge trimmings or shreddings as may be contained inshredded or reground reinforced composites containing such fibers in anexisting polymer matrix. In other words, an existing thermoplasticpolymer matrix having one or more of the above molding materials 14 maybe, for example, shredded and used.

[0098] The compatibility enhancing agent or agents 198 are heatactivated and are chosen so as to enhance the compatibility of thethermoplastic polymers, such as glass or glass fibers, and any otherreinforcements or fillers which may be added. For example, olefinicpolymers grafted with polar functional moieties such as acrylic acid ormaleic anhydride may be mentioned. In this regard, the “Polybond”products available from BP Chemicals are presently preferred for use.

[0099] Preliminary studies have indicated that “Polybond” product grades1000, 1001, 1002 and 1003 are suitable compatibility enhancing agents198 that may be added to the thermoplastic polymers and fillers 196.These particular “Polybond” products are polypropylene based couplingagents grafted with CA. 6% acrylic acid. The only difference betweenthese 4 grades of “Polybond” materials is in the melt flow rate “mfr”.These range from 100 g/10 min. (“Polybond” 1000) to 12 g/10 min.(“Polybond” 1003). The skilled artisan can choose the particular desiredmfr based upon the identity of the materials fed to the plasticator 12and the initial processing viscosity thereof desired. Other exemplarycompatibility enhancing agents 198 include “Polybond 1009 and 3009”,both available from BP Chemicals. These polymers can be described ashaving high density polyethylene backbones grafted with either acrylicacid or maleic anhydride. The 1009 product is grafted with CA. 6%acrylic acid having a melt index of 6 g/10 min. while “Polybond” 3009 isgrafted with about 2% maleic anhydride and has a melt index of about 6g./10 min.

[0100] Other “Polybond” products can also be mentioned as beingexemplary. These include the polypropylene based polymers grafted withvarying amounts of maleic anhydride. For example, “Polybond” 3001 isdescribed as a polypropylene polymer with grafted maleic anhydridebranches present at a level of about less than 1/4%. This productexhibits a melt flow rate of about 5 g./10 min. “Polybond” 3002 is alsoexemplary and is similar to the 3001 product except that its maleicanhydride content is about twice as high and that it exhibits a MFR of 7g./10 min.

[0101] Additionally, free radical generating polymerization catalystssuch as peroxides may be admixed with ethylenically unsaturated acids oranhydrides and used herein as compatibility enhancing agents.

[0102] Other exemplary compatibility enhancing agents include theEPOLENE polymers available from Eastman Chemical and other experimentalnucleating agents also available from Eastman and that are specificallyformulated for polyester rather than olefins. EPOLENE is a trademark ofEastman Chemical.

[0103] The compatibility enhancing agent 198 which are normally fed tothe feed hopper 36 in an amount of 1 to 10 (% by weight) based upon theweight of the thermoplastic polymeric material used.

[0104] An advantage of the system 10 is that it is capable of handlingpost consumer molding materials or molding materials which have arelatively high degree of contamination. For example, the moldingmaterials 14 may be commingled or contaminated polymeric material astypically found in the post consumer waste stream. While the nature ofcontaminants and the percent of occurrence varies from lot to lot as anatural feature of waste materials, they do, on average, typicallycontain similar materials and in similar quantities. For example, postconsumer polyesters (collected in the waste stream as PET) used in thisprocess may contain 90% PET, 5% HDPE, 2% PP, 0.5% EVA and the remaindercontaminants, including such things as miscellaneous paper and aluminumscrap.

[0105] The invention will now be described with reference to a number ofspecific examples which are to be regarded solely as illustrative andnot as restricting the scope of the invention.

EXAMPLE 1

[0106] First, molding materials were used without the compatibilityenhancing agent 198. Sixty (60) parts of a mixed post consumer polymerbatch comprising PET, HDPE, PP and ethylene vinyl acetate (EVA) and 40parts of scrap (landfill destined) glass fiber edge trimmings havingnominal 2 inch fiber lengths were charged to the single reciprocatingscrew plasticizer shown in FIG. 1. Compounding the billet 16 occurred ina single thermodynamic cycle with a temperature rise to 430 degreesFahrenheit for a period of 30 seconds, at which time the resulting mixedand molten bulk molding billet 16 was delivered to the press where a6″×9″ sample, 0.150 inch thick, was molded at a pressure of 3000 psi.The molded billet 16 was subjected to physical property tests and wasfound to exhibit a flexural strength of 10,300 psi, a flexural modulusof 700,000 psi and a notched IZOD of 0.43. These characteristics arerepresentative of a strong but brittle material considered to haveminimum desirability in product fabrication.

EXAMPLE 2

[0107] A mix of one-half post consumer polyethylene terephthalate (PET)derived from soft drink bottles and one-half shredded scrap from a 40%glass reinforced polypropylene composite material resulting in shortchopped glass lengths was charged to the plasticizer 12 shown in FIG. 1.Compounding in the barrel 8 occurred at 500 degrees Fahrenheit to 550degrees Fahrenheit for a time period of 60 seconds. The sample wastested and exhibited an average 12,500 psi flexural strength, a 435,000psi flexural modulus, and a notched IZOD of 5.7 ft.-lbs./inch. Thisrepresents a material with performance satisfactory for a wide range ofproduct uses.

EXAMPLE 3

[0108] Another example includes the use of the compatibility enhancingagent 198. Sixty (60) parts of a mixed (commingled and contaminated)post consumer polymer batch and 40 parts of scrap (landfill destined)glass fiber edge trimmings with nominal 2″ fiber lengths were charged tothe plasticizer 12 shown in FIG. 1. The polymer material was primarilyPET, but also contained polycarbonate, HDPE, polypropylene, EVA andnon-polymer material such as scrap from aluminum cans and paper. Acompatibility enhancing agent 198 (Polybond 3009) was added to the mixin the plasticizer 12 at a ratio of 3% by weight based upon the weightof polymeric material fed. The first, second and third predeterminedtemperatures were set at 490 degrees Fahrenheit, 520 degrees Fahrenheit,530 degrees Fahrenheit, respectively, in the feeding plasticating area,and 540 degrees Fahrenheit in the delivery area. The knife head 96 wasset to 550 degrees Fahrenheit. The distance sensor was set a 110 mm. Theplasticizer 12 was operated with a screw speed of 20-40 rpm andcylinders 88 and 90 were set at 300 psi such that pressure of 50 psibuilding to 300 psi resulted in the reciprocating screw 42 being pushedby barrel back pressure to the 110 mm position. At this time (afterabout three total minutes from introduction of materials to theplasticizer 12), a mixed and molten billet 16 was then delivered to thepress 18 with mold faces 20 a and 20 b thereof heated to 80 degreesFahrenheit. A 6″×9″ sample, 0.150 inch thick, was then molded at apressure of 3,000 psi. The sample was tested and exhibited a flexuralstrength of 20,310 psi, a flexural modulus of 980,000 and a notched IZODof 3.03 ft.-lbs./inch. This material would be suitable for a wide rangeof product applications having strength and modulus properties analogousto commercially available and widely used glass reinforced thermoplasticsheet materials.

[0109] A method and process for using system 10 and for creating inbillet 16 for molding a part will now be described. First, apost-consumer recyclable plastic, such as PET, polypropylene,polyethylene and ethylene vinyl acetate are collected as shown at step200. If desired, these recyclable polymers may be separated (forexample) by flotation separation (as shown in block 202). Thecontaminated polyesters 192 and carbocylics 194 along with thepreselected reinforcements and fillers 196 are loaded into feed hopper36 (FIG. 1) of plasticator 12 as shown in block 204. As mentionedearlier herein, the compatibility enhancing agent 198 may also be addedat this time, if desired.

[0110] It may be desirable to preheat the molding materials (block 206),in which case controller 30 energizes preheater 48 to preheat themolding materials 14 (block 208) to approximately 100□ to 350□ F,depending on the molding materials 14 selected. Controller 32 thenenergizes drive motor 42 to rotatably drive agitator 40 to begin mixingthe molding materials 14 in feed hopper 36.

[0111] At block 210 a billet 16 is plasticized. Depending upon the partbeing molded, the predetermined characteristics of billet 16 aredetermined. Thus, the volume, density and length, for example, of billet16 are determined. Once determined, the variable pressure regulator 117associated with cylinders 88 and 90 is adjusted to a pressure whichgenerally corresponds to the billet characteristics selected. Inaddition, one or more of the contact switches 140 of distance sensor 134are adjusted to correspond to the length and volume of the billet 16desired. In addition, the variable pressure regulator 117 associatedwith drive motor 92 is also adjusted so that drive motor 92 drives screw32 at an appropriate rpm. The controller 32 is also programmed with thefirst, second and third predetermined temperatures so that heatingcontroller 158 energizes the plurality of heaters 152, 154 and 156 toheat the feeding, blending and extruding portions 54, 56 and 58 to theappropriate temperature. For purposes of illustration only, it will beassumed that the pressure regulator 117 was set at 300 psi, the powersystem 96 pressure was set at 1000 psi, and the pressure regulatorassociated with drive motor 92 was set at 25 rpm, with contact switch140 being set at approximately 110 millimeters.

[0112] The molding materials 14 are then introduced to the feedingopening 46 (FIG. 5). As best illustrated in FIGS. 4-10, controller 32energizes drive motor 92 of screw drive system 75 to rotatably drivescrew 30 such that the molding materials 14 are gradually blendedtogether into a mixed molten suspension period.

[0113] The molding materials 14 are heated to approximately the firstpredetermined temperature when they are introduced between feedingportion 54 of barrel 28 and feeding section 60 of screw 30. Note that,due to depth 72 (FIG. 3) and pitch of the flights of the first pluralityof threads 66, the molding materials 14 start to become blended suchthat the reinforcing fibers, like glass fibers, are not damaged. Asscrew 30 rotates in the direction of arrow 31 in FIG. 5, the moldingmaterials 14 are forced from the feeding section 60 of screw 30 to theblending section 62 which is associated with blending portion 56 ofbarrel 28 when the screw 30 is in the home position shown in FIGS. 3 and4. Notice also that because of the taper of the core 30 a of screw 30,the molding materials 14 become blended into a more homogeneoussuspension at the blending section 62 where the suspension is heated toapproximately the second predetermined temperature mentioned earlierherein. To further facilitate the mixing and blending of the moldingmaterials 14, the screw 30 may be provided with a blending section 62having a second plurality of threads 68 (FIG. 4) with a pitch which isgenerally smaller than the pitch of the first plurality of threads 66.Varying the number of threads per inch, pitch of threads and threaddepth facilitates accurately controlling the suspension and blendingtime of the molding materials 14, controlling the volume and density ofbillet 16, and controlling the velocity at which the molding materials14 are plasticated.

[0114] As the screw drive system 75 continues to drive screw 30 asmentioned above, the mixed suspension is forced toward the storage area124 associated with the extruding portion 58 of barrel 28. In thestorage area 124, the molten suspension is collected, further blendedand heated to approximately the third predetermined temperature. Themixed molten suspension ultimately engages the side 120 a (FIG. 5) ofknife 120 and begins forming billet 16 as shown in FIG. 6. As the moltensuspension continues to collect in storage area 124, the pressure beginsto build.

[0115] As the pressure approaches or exceeds 300 psi (i.e., the pressureapplied to cylinders 88 and 90) the biasing pressure of cylinders 88 and90 is overcome and the screw 30 begins withdrawing from passageway 52,thereby causing slidable block 78 to move in the direction of arrow 122(FIG. 1). As shown in FIGS. 6-8, the molten suspension begins buildingin the storage area 124. The slidable block 78 moves in the direction ofarrow 122 until contact switch 140 contacts switch 138 to generate thedistance signal which is received by controller 32. Controller 32 thenenergizes pressure valves 114 and 116 to stop drive motor 92. Controller32 also energizes pressure valve 110 to energize knife drive 118 tocause knife blade 120 to move from the closed position (FIGS. 8 and 14)to an open position (FIGS. 9 and 15). Controller 32 then energizespressure valves 108 and 110 to actuate cylinders 88 and 90 to pullslidable block 78 in a direction opposite arrow 122, thereby causing themolten suspension to be extruded through extruding opening 132 (FIGS. 9and 15). Controller 32 may then energize pressure valve 112 to actuateknife driver 118 to force knife blade 120 into the closed position,thereby separating the molten suspension to provide billet 16.

[0116] Although not shown, it should be appreciated that the controller32 may cause the screw drive 75 and knife assembly 162 to provide aplurality of billets 16 during a single stroke length of the cylinders88 and 90.

[0117] The billet 16 may then be conveyed (block 212 in FIG. 16) to moldmember 20 b in press 18 by the conveyance system 190 (FIG. 1). Othermaterials, such as sheet coating material or reinforcement material maybe prepositioned (block 211) in the lower mold member 20 b prior tointroducing billet 16 into the mold member 20 b. Once located in thepress 18, controller 32 may energize press controller to, in turn,energize press driver 176 to drive platform 180 downward (as viewed inFIG. 1) to cause the part to be molded. In the example being described,the mold heater 182 heats the molding members 20 a and 20 b toapproximately 80 degrees Fahrenheit. In addition, the press 18 is set tocompress billet 16 at approximately 3000 psi with a controlled pressuregradient.

[0118] At block 214 (FIG. 16b), the part is then molded by press 18.

[0119] As shown in decision block 216, it may be desirable to perform asecond operation on the part before it is removed from the press 18 orwhen the billet 16 is molded. If such an operation is desired, it isconducted (block 218) and then the part is removed from the press 18(block 220). In this regard, a second operation may comprise painting orotherwise placing a coating on the part, hot stamping a decal on thepart, partially assembling the part, or molding or embossing a symbol onthe part. If a second operation is not performed on the part, the partis removed from the press 18 at block 222.

[0120] Note that it may be desirable to integrally mold a surfacetexture or finish to the part during the molding process. For example, aplastic sheet or film, such as the Teslin sheet, manufactured by PPGIndustries of Pittsburgh, Pennsylvania, may be integrally molded intothe surface of the part. For example, if the plastic sheet was selected,it would be cut to the dimensions of the mold and placed in the moldprior to molding. The side of the sheet which contacts the mold may becoated with an acrylic finish to prevent the sheet from adhering to themold during the molding process. After the sheet is placed in the mold,the billet 16 can be placed on the sheet and the part molded asdescribed. If desired, a sheet could be placed on both mold members 20 aand 20 b before billet 16 is placed on mold member 20 a. The billet 16would then be placed on the sheet and molded as described above. Thisfacilitates producing a part having a desired surface texture or finishon both sides. It is to be noted that, after the molding process, thepolymer sheet is integral with the part.

[0121] It should be appreciated that other types of materials may beintegrally molded into the part or into the surface of the part. Forexample, wood veneer sheets, burlap, or metal wire mesh may be moldedinto the part or into the surface of the part.

[0122] Returning to block 224 in FIG. 16b, once the molding process iscompleted and the part is removed from the press, the process can berepeated for another part. At block 226, subsequent operations, such asadditional graphics, sheet material or printing, assembly, packaging andthe like may be performed on the part.

[0123] Advantageously, this invention provides a system and method forusing relatively highly contaminated post-consumer polyesters andcarbocylics (such as olefinics). The system and method also facilitatesevenly mixing reinforced fibers having a length of 2.0 inches or more,without damaging the fibers during the compounding, plasticating,extrusion and compression molding process.

[0124] Such post-consumer scrap would normally require additionalcleaning and separation before use. This invention provides an apparatusand process for using the contaminated post-consumer materials toproduce a part which has physical, chemical and mechanical propertiessimilar to non-recycled materials.

[0125] Further, the method and apparatus provides a system for moldingthe molding materials 14 into a part using only a single thermal heatrise by controlling, coordinating and sequencing the temperature rise ofthe molding materials 14 as they go through the system 10. Using thesingle thermal heat rise facilitates enhancing the molecular orientationof the polymers which, in turn, causes the resultant part to haveenhanced strength characteristics when compared to other types ofmolding processes. Also, a single heat rise facilitates reducing thematerial degradation that occurs to thermoplastic materials when theyare heated. Further, because the pressures in the press 18 areadjustable, the surface texture or finish or the resultant part can becontrolled to enhance the aesthetic or functional appeal of the part.

[0126] The invention also provides a method and apparatus which isadvantageous because it reduces or eliminates many of the intermediatehandling and thermocycles from receipt of the post-consumer materials tothe molding of the part.

[0127] The described method and apparatus may utilize compatibilityenhancing agent 198 which promote chemical bonding, for example, byincreasing the presence of hydroxyl groups and the reinforcing fiberswhile they aid in the dispersion of reinforcement within the moltensuspension.

[0128] Finally, molecular orientation within the billet 16 is enhancedby controlling the compression pressures and temperatures in press 18.

[0129] Advantageously, it should be appreciated that long fiber lengthcan be maintained by reducing the tortuous nature of the material pathexisting in many prior art devices and processes. This improvement ofthe path results from screw thread depths that allow fibers to moveintact, allowing the screw to float on a film of molten material betweenitself and the barrel. The lack of small orifices in delivering thematerial through the plasticator 12 and the molding process allowsforming without constraining the movement of fibers to form the part.

[0130] Referring now to FIGS. 17-20, another embodiment is shownillustrating the use of the system and method for molding an item ofsporting goods equipment, such as a basketball board 200 (FIG. 18). Inthis embodiment, the press 18 comprises the upper molding member 20 a′and lower molding member 20 b′ which cooperates to protect the backboard200 illustrated in FIGS. 18 and 20. Although not shown, the uppermolding member 20 a′ comprises a rib forming section (not shown) forforming a plurality of ribs 202 (FIGS. 19 and 20) which facilitatesstrengthening the basketball backboard 200 as conventionally known. Thelower mold member 20 a′ comprises a plurality of recess-forming areas201 for forming angled recesses 207 (FIG. 18) in backboard 200.

[0131] As mentioned earlier herein, the system and method of the presentinvention causes the resultant part (in this case, the basketballbackboard 200) to have enhanced strength characteristics when comparedto other types of molding processes. This, in turn, facilitates reducingthe number of reinforcing or rib members 202 and also facilitatesreducing the material and manufacturing costs associated with producingbackboard 200 in the manner described herein.

[0132] As mentioned earlier, it may be desirable to integrally mold asurface texture or finish to the part during the molding process. In theembodiment being described, a plastic sheet or film 204 (FIG. 17) may beprovided comprising a front side 204 a and a backside 204 b whichbecomes molded such that it is an integral part of the backboard 200. Itshould be appreciated that the sheet 204 comprises graphics 206 orprinted information on the front surface 204 a which faces outward awayfrom backboard 200. In this regard, the printing information maycomprise a company name, association affiliation, rectangular target,such as target 208 in FIG. 18, or other graphics as may be desired.

[0133] In the embodiment being described, the mold member 20 b′ (FIG.17) may comprise a plurality of locating pins 210 which cooperate withthe plurality of holes or apertures 212 on sheet 204 to facilitatelocating the sheet mold member 20 b′.

[0134] The lower mold member 20 b′ may also comprise a plurality of pins216 which form a plurality of holes 220 (FIG. 18) for mounting backboard200 onto a frame or pole (not shown) using suitable fasteners, such asbolts and the like. Notice also that locating pins 210 facilitatedefining holes 222 (FIG. 20) for attaching a rim (shown in phantom inFIG. 18) using suitable fasteners, such as bolts, screws and the like(not shown).

[0135] It should also be appreciated that the mold member 20 b′ may betextured or roughened in order to facilitate preventing the sheet 204from moving once it is placed onto mold member 20 b′ as described below.In this regard, it has been found that sandblasting a surface 214 ofmold member 20 b′ provides enough texture to facilitate preventing thesheet 204 from moving on mold member 20 b′. Also, an electric charge maybe put to the sheet 204 before or after the sheet is placed in the mold.This also facilitates preventing the sheet 204 from moving on moldmember 20 b′.

[0136] Notice that the lower mold member 20 b′ may comprise a graphicsheet receiving area 222 (FIG. 17) and a bordering raised area 224. Inthis regard, it should be appreciated that the border area 224facilitates defining a molded border 226 (FIG. 18) having a surface 226a (FIG. 19) which is generally co-planer with surface 204 a of sheet 204after the sheet 204 is compression molded as described.

[0137] In operation, the upper and lower mold members 20 a′ and 20 b′are mounted on press 18 in a manner conventionally known. When it isdesired to mold backboard 200, the sheet 304 is placed onto lower moldmember 20 b′. Next, the conveyance system 190 (FIG. 1) positions billet16 onto sheet 204 in mold member 20 b′ after billet 16 is extruded fromthe extruding end 28 b of barrel 28 of plasticator 12. As mentionedearlier herein, other materials, such as sheet coating material orreinforcement material may be preposition (block 211 in FIG. 16) in thelower mold member 20 b′ prior to introducing billet 16 into the moldmember 20 b′. As also mentioned previously herein, sheet 204 or side 204b of sheet 204 which contacts upper mold member 20 a′ may be coated witha finish to prevent the sheet 204 from adhering to the mold member 20 a′during the molding process.

[0138] Once the sheet 204 and billet 16 are positioned between moldmembers 20 a′ and 20 b′ as illustrated in FIG. 17, controller 32 mayenergize press controller 178 to, in turn, energize press driver 176(FIG. 1) to drive platform 180 downward as viewed in FIG. 1 to cause thepart (i.e., the backboard 200) to be molded.

EXAMPLE 4

[0139] An illustration for molding backboard 200 will now be described.First, billet 16 is formed when plasticator 12 is charged with a mixtureof about 83% mixed recycled thermoplastic polyolefins mentioned earlier,1% compatibility enhancing agent, and 16% glass longer than one-quarterinch. The mixture is heated to a temperature of 450 degrees fahrenheitwhile being blended into the homogeneous billet 16 in the plasticator12, and is collected in the plasticator storage area 124 at a pressureof 300 psi.

[0140] The backboard mold members 20 a′ and 20 b′ in the compressionmolding press 18 are set to a temperature of about eighty degreesfahrenheit and the mold is prepared for molding the part by properlyorienting a printed sheet 204 of the aforementioned Teslin with theprinted side 204 a face down in the mold member 20 b′. The plasticator12 is set to deliver about a thirteen pound billet 16 which istransferred by conveyor system 190 to the press 18 and placed atop theTeslin® sheet 204. The compression molding press 18 is then closed anddelivers a pressure of about 2,000 psi for thirty seconds, at which timethe pressure reduces to 500 psi for another thirty seconds. The press 18is then opened and the finished backboard 200 with integrally moldedgraphic sheet 200 is removed from the press 18.

[0141] It should be appreciated that the upper and lower mold members 20a′ and 20 b′ are at a lower temperature (i.e., about 80 degreesfahrenheit) relative to billet 16 which is relatively much hotter (i.e.,on the order of between 300 to 500 degrees). Because of this temperaturedifferential, the molten billet 16 tends to bond quickly to the backsurface 204 b of sheet 204 during the compression molding process. Asthe molten plastic or billet 16 cools, the graphic sheet 204 becomesintegral with backboard 200. The temperature differential alsofacilitates melting the Teslin® at a rate such that it cools beforemelting graphics 206 on surface 204 a.

[0142] After the backboard is molded, backboard 200 may subsequently bemounted onto a suitable frame (not shown) which, in turn, is mounted ona pole or other support structure for supporting the backboard 200 abovethe ground.

EXAMPLE 5

[0143] In another embodiment of the invention, a process for makingpoint-of-purchase display or sign 300 (FIG. 21). The plasticator 12 ischarged with a mixture of 95% mixed recycled thermoplastic polyolefinsand 5% glass longer than one-quarter inch. The mixture is heated to atemperature of 450 degrees fahrenheit while being blended into ahomogeneous material in the plasticator 12, and is collected in theplasticator storage area 124 at a pressure of 300 psi. The point ofpurchase display product mold (not shown), which comprises a shape whichcomplements the shape of the display 300, is placed in the compressionmolding press 18 and is set to a temperature of about 80 degreesfahrenheit. The mold is prepared for molding the display 300 by properlyorienting a lithographically printed side 302 of a sheet of Teslin®having desired printed information situated face down in the mold. Theplasticator 12 is set to deliver a ten ounce billet 16 which istransferred to the mold and placed atop the Teslin® sheet. Thecompression molding press 18 is then closed and delivers a pressure of2,000 psi for fifteen seconds at which time the pressure reduces to 500psi for another twenty-five seconds. The press 18 is then opened and thefinished point of display or sign 300 with printed graphic sheetintegrally molded therein is removed from the mold.

[0144] While the invention has been described with reference to certainspecific embodiments, this description is merely illustrative, and isnot to be construed as limiting the scope of the invention. Variousother modifications and changes may occur to those skilled in the artwithout departing from the spirit and scope of the invention as definedby the appended claims.

1. A plasticating process comprising the steps of: loading a plasticatorwith a plurality of molding materials; creating a mixture with theplurality of molding materials in the plasticator; and plasticating themixture of said plurality of molding materials at a controlledtemperature and pressure in order to create a billet havingpredetermined billet characteristics.
 2. The process as recited in claim1 wherein said method further comprises the step of: molding the billetinto a part.
 3. The process as recited in claim 2 wherein said methodfurther comprises the step of: molding the billet into a part havinggraphic images molded into its surface.
 4. The process as recited inclaim 3 wherein said method further comprises the step of: using acompression press.
 5. The process as recited in claim 2 wherein saidmolding step further comprises the step of: using a compression press tomold the billet into a part.
 6. The process as recited in claim 2wherein said loading step comprises the step of: loading a plurality ofthermoplastic polymers and long reinforcing fibers into the plasticator.7. The process as recited in claim 6 wherein said plurality of materialscomprise about 60-95% thermoplastic polymers and 5-40% reinforcingfibers.
 8. The process as recited in claim 1 wherein said loading stepincludes the step of: loading a compatibility enhancing agent into theplasticator.
 9. The process as recited in claim 1 wherein saidcompatibility enhancing agent is an olefinic polymer grafted with polarfunctional moieties such as acrylic acid or maleic anhydride.
 10. Theprocess as recited in claim 6 wherein said thermoplastic polymers arecontaminated.
 11. The process as recited in claim 10 wherein saidcontamination is on the order of about 10%.
 12. The process as recitedin claim 3 wherein said process further comprises the step of: cleaningsome of the molding materials before the loading step.
 13. The processas recited in claim 2 wherein said molding step further comprises thestep of: molding a surface texture onto the part.
 14. The process asrecited in claim 2 wherein said method further comprises the step of:performing a second operation on the part.
 15. The process as recited inclaim 14 wherein said performing step comprises the step of: molding thepart with a predetermined surface characteristic.
 16. The process asrecited in claim 15 wherein said predetermined surface characteristic isa preselected pigment.
 17. The process as recited in claim 14 whereinsaid performing step comprises the step of: printing information on thepart.
 18. The process as recited in claim 2 wherein said process furthercomprises the step of molding a predetermined feature into the part. 19.The process as recited in claim 18 wherein said predetermined feature isa wood finish.
 20. The process as recited in claim 18 wherein thepredetermined feature is a reinforcement.
 21. The process as recited inclaim 1 wherein said compatibility enhancing agent comprises an olefinicpolymer grafted with polar functional moieties such as acrylic acid ormaleic anhydride.
 22. The process as recited in claim 1 wherein saidprocess further comprises the steps of: laying a sheet in a mold formolding a part; laying said billet on said sheet; integrally moldingsaid sheet into said part.
 23. The process as recited in claim 22wherein said part has a graphic image molded into its surface.
 24. Theprocess as recited in claim 22 wherein said method further comprises:molding a part having a graphic image molded into its surface.
 25. Theprocess as recited in claim 22 wherein said method further comprisingthe steps of: laying a sheet into said mold, said sheet comprises agraphic image on a side thereof; integrally molding said sheet into saidpart.
 26. The process as recited in claim 22 wherein said processfurther comprises the step of: applying a finish to said sheet beforesaid sheet is placed in said mold.
 27. The process as recited in claim26 wherein said process further comprises the step of applying anacrylic finish to said sheet before said sheet is placed in said mold.28. The process as recited in claim 2 wherein said process furthercomprises the step of molding a symbol on the part.
 29. The process asrecited in claim 28 wherein said process further comprises the step of:molding a part having a graphic image molded into its surface.
 30. Theprocess as recited in claim 21 wherein said process further comprisesthe step of: using a mold having a first mold member having a surfaceand a complementary mold member which cooperates with said first moldmember to mold said part; said surface being textured to facilitatepreventing said sheet from slipping in said mold.
 31. A process formolding a part comprising the steps of: placing a sheet into a moldprior to molding; placing a billet onto said sheet; compression moldingthe sheet and said billet to produce a part such that said sheet becomesintegrally molded with said part.
 32. The process as recited in claim 31wherein said process further comprises the step of: blending said billetusing a plurality of thermoplastic polymers and a plurality ofreinforcing fibers into the plasticator.
 33. The process as recited inclaim 32 wherein said blending step further comprises the step of:blending about 60-95% thermoplastic polymers with about 40-5%reinforcing fibers.
 34. The process as recited in claim 32 wherein saidthermoplastic polymers are contaminated.
 35. The process as recited inclaim 31 wherein said sheet comprises a graphic.
 36. The process asrecited in claim 31 wherein said process further comprises the step of:compression molding said sheet and said billet to produce a part havinga graphic image molded into its surface.
 37. The process as recited inclaim 36 wherein said process further comprises the step of: using asheet comprising basketball graphics.
 38. The process as recited inclaim 36 wherein said process further comprises the step of: blendingsaid billet using a plurality of thermoplastic polymers and a pluralityof reinforcing fibers.
 39. The process as recited in claim 38 whereinsaid blending step further comprises the step of: blending approximately60-95% polymers with about 40-5% reinforcing fibers.
 40. The process asrecited in claim 38 wherein at least one of said thermoplastic polymersare contaminated.
 41. The process as recited in claim 31 wherein saidprocess further comprises the step of: applying a finish to said sheetprior to placing said sheet in said mold.
 42. The process as recited inclaim 41 wherein said process further comprises the step of: applying anacrylic finish to said sheet.
 43. The process as recited in claim 31wherein said process further comprises the step of: providing a moldhaving at least one textured surface for preventing said sheet frommoving in the mold during said compression molding step.
 44. The processas recited in claim 31 wherein said process further comprises the stepof: compression molding said part such that a border is situated aroundsaid sheet.
 45. The process as recited in claim 44 wherein said processfurther comprises the step of: compression molding said part such thatsaid border is co-planar with said sheet after said part is molded. 46.The process as recited in claim 31 wherein said process furthercomprises the step of cuffing said sheet such that it comprisesdimensions which generally correspond to the dimensions of said mold.47. A molded part comprising: a compression molded part molded from aplurality of materials comprising a predetermined amount of areinforcing fiber and thermoplastic polymers; and a sheet integrallymolded into said part, said sheet comprising a graphics side facing awayfrom said part.
 48. The molded part as recited in claim 47 wherein saidthermoplastic polymers are contaminated.
 49. The molded part as recitedin claim 47 wherein said thermoplastic polymer is an olefinic which iscontaminated.
 50. The molded part as recited in claim 47 wherein saidreinforcing fibers are glass fibers comprising a length of at least 2inches.
 51. The molded part as recited in claim 47 wherein saidplurality of materials further comprises a compatibility enhancingagent.
 52. The molded part as recited in claim 51 wherein saidcompatibility enhancing agent comprises an olefinic polymer grafted withpolar functional moieties such as acrylic acid or maleic anhydride. 53.The molded part as recited in claim 47 wherein said part is a basketballbackboard.
 54. The molded part as recited in claim 47 wherein said sheetis integrally molded with said plurality of materials to define a borderarea.
 55. The molded part as recited in claim 53 wherein said sheet isintegrally molded with said plurality of materials such that said bordercomprises a surface which is co-planar with said sheet.
 56. A basketballbackboard comprising: a backboard member molded from a plurality ofmaterials comprising a predetermined amount of a reinforcing fiber andthermoplastic polymers; and a sheet integrally molded into saidbackboard member, said sheet comprising a graphics side facing away fromsaid part.
 57. The molded part as recited in claim 56 wherein saidthermoplastic polymers are contaminated.
 58. The molded part as recitedin claim 56 wherein said reinforcing fibers are glass fibers comprisinga length of at least 2 inches.
 59. The molded part as recited in claim56 wherein said plurality of materials further comprises a compatibilityenhancing agent.
 60. The molded part as recited in claim 59 wherein saidcompatibility enhancing agent comprises an olefinic polymer grafted withpolar functional moieties such as acrylic acid or maleic anhydride. 61.The molded part as recited in claim 56 wherein said part weighs over tenpounds.
 62. The molded part as recited in claim 56 wherein said sheet isintegrally molded with said plurality of materials to define a borderarea.
 63. The molded part as recited in claim 62 wherein said sheet isintegrally molded with said plurality of materials such that said borderlies in a plane which is coplanar with a plane in which said sheet lies.64. The molded part as recited in claim 56 wherein said backboard memberis molded from a recycled thermoplastic comprising at least one materialselected from the group consisting essentially of a polyester,contaminated polymeric material, a polyolefin, and a compatibilityenhancing agent comprising at least one material selected from the groupconsisting of olefinic polymers grafted with polar functional moietiessuch as acrylic acid or maleic anhydride, and said reinforcing fillercomprises at least one material comprising at least one of thefollowing: a reinforcing fiber, a glass fiber, fly ash, clay, carbon orgraphite fiber, and shredded fiber reinforced composite material. 65.The process as recited in claim 3 where said part is a basketballbackboard.
 66. The process as recited in claim 23 where said part is abasketball backboard.
 67. The molded part as recited in claim 24 wheresaid part is a basketball backboard.
 68. The process as recited in claim25 where said part is a basketball backboard.
 69. The process as recitedin claim 29 where said part is a basketball backboard.
 70. The processas recited in claim 38 where said part is a basketball backboard. 71.The process as recited in claim 3 where said part is a point of purchasedisplay.
 72. The process as recited in claim 23 where said part is apoint of purchase display.
 73. The process as recited in claim 24 wheresaid part is a point of purchase display.
 74. The process as recited inclaim 29 where said part is a point of purchase display.
 75. The processas recited in claim 38 where said part is a point of purchase display.76. The process as recited in claim 47 where said part is a point ofpurchase display.